A chromium-nickel alloy steel containing copper

ABSTRACT

An alloy steel for high temperature applications, such as for compressor and turbine discs in gas turbines consists essentially of: 0.02-0.25 percent carbon, 0.05-1.5 percent silicon, 0.1-1.5 percent manganese, 7.0-12.0 percent chromium, 0.2-4.0 percent nickel, 0.2-5.0 percent molybdenum, 0.10-0.60 percent vanadium, 0.05-0.70 percent niobium, up to 7.0 percent cobalt, up to 5.0 percent copper, 0.002-0.03 percent boron, at least 0.010 percent but less than 0.050 percent nitrogen, the balance, apart from incidental impurities being iron.

United States Patent Kirby et al.

[54] CHROMIUM-NICKEL ALLOY STEEL CONTAINING COPPER [72] lnventors: Henry William Kirby; Arthur l-logg, both of Sheffield, England [73] Assignee: Firth Brown Limited, Sheffield, England [22] Filed: June 19, 1969 [21] Appl. No.: 834,878

[30] Foreign Application Priority Data June 20, 1968 Great Britain ..29,473/68 [52] US. Cl. ..75/125, 75/128 B, 75/128 W, 75/128 V, 75/128 N [51} Int. Cl ..C22c 39/54, C22c 39/20 [58] Field of Search ..75/128 V, 128 G, 128 W, 128 F, 75/128 N, 128 0,125

[56] References Cited UNITED STATES PATENTS 2,793,113 5/1957 Rait ..75/128V 1 May 16, 1972 FOREIGN PATENTS OR APPLICATIONS 212,628 l/l958 Australia ..75/128 G Kirkby ..75/128 G Lula ..75/l28 V Primary Examiner-Hyland Bizot Attorney-Buell, Blenko & Zcisenheim ABSTRACT 12 Claims, No Drawings A C I'IROMIUM-NICKEL ALLOY STEEL CONTAINING COPPER BACKGROUND OF THE INVENTION This invention concerns improvements in or relating to alloy steels for high temperature applications, and in particular to alloy steels suitable for use in the fabrication of compressor and turbine discs in gas turbines and in similar applicatrons.

SUMMARY OF THE INVENTION According to the present invention there are provided alloy steels having the following percentage weight composition:

0.050 the balance being iron and incidental impurities.

In cases where optimum creep resistance is required combined with high proof, plain and notched tensile strength, compositions in the following ranges, in percentages by weight, are preferred:

Carbon Silicon Manganese Chromium Nickel Molybdenum Vanadium Niobium Cobalt Copper Boron Nitrogen 0. 05 at least 0.010 but less than 0.050 the balance being iron and incidental impurities.

DESCRIPTION OF THE PREFERRED EMBODIMENTS l Typical examples of such a composition are as follows:

Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5

C 0.05 0.07 0.06 0.07 0.04 Si 0.45 0.50 0.45 0.40 0.20 Mn 0.80 0.80 0.85 0.90 0.75 Cr 10.5 9.0 10.7 10.5 10.1 Ni 0.5 0.4 0.4 0.5 0.3 M 1.5 1.5 1.6 1.6 1.5 V 0.22 0.20 0.21 0.21 0.22 Nb 0.45 0.60 0.46 0.46 0.48 Co 4.0 4.0 4.2 4.2 4.2 Cu 2.0 1.35 1.8 2.9 2.0 B 0.010 0.010 0.010 0.012 0.009 N, 0.025 0.020 0.025 0.012 0.031

Iron and incidental impurities: Balance Following are the results which have been obtained as a result of the application of the standard tests to alloy steels of such composition:

(1) Tensile tests (1) Tensile tests Ex 1 Ex. 2 E123 E124 Ex. '1

0.1% proof stress (tons/sq.

in. 47 46 47 47 45 Ultimate tensile strength (tons/sq. in.) 60 58 60 60 51* Percentage elongation 14 15 12 1G 15 Reduction of area (percent) 45 52 40 64 (i7 (2) Creep tests T.P.S. for 32 tons/sq. in.

at 550 C. in holu's 0.130 0.170 0.127 0. 150 0.

In cases where higher proof and tensile strength are required together with a better impact strength and good creep resistance compositions falling within the following percentage weight ranges are preferred:

Carbon Silicon Manganese Chromium Nickel Molybdenum Vanadium Niobium Cobalt Copper Boron Nitrogen 3 5 p to 2.0 0.005 0.020 at least 0.010 but less than 0.050 the balance being iron and incidental impurities.

DESCRIPTION OF THE PREFERRED EMBODIMENTS (2) Typical examples of this second preferred type of composition are as follows:

Iron and incidental impurities: the balance.

(1) Tensile tests Ex. 6 Ex. 7 Ex. 8 Ex. 0 Ex. 10

(a) Room terrftpsratuzg:

0.1 r00 5 ress bus 5 11?. 72 73 64 70 72 Ultimate tensile strength (tons/sq. in.) 95 90 83 96 98 Percentage elongation 21 20 18 10 '20 Percentage reduction of area. 61 59 59 60 60. N.'I.S. 156 159 136 164 (b) 300 0.: f t (t .1 mo s ress ons s izfl. 50 4!) 43 50 51 Ultimate tensile strength F (tons/sq. in.) 70 70 62 13 74 Percentage elongation 10 15 16 17 10 Percentage reduction of area 53 53 65 66 64 N.'I.S. (tons/sq. in.) 118 117 (2) Impact tests Charpy V Notch (IL/lbs.)

We claim: 6. An alloy according to claim 1 consisting essentially of the 1. An alloy consisting essentially of the following elements following elements in the stated weight percentages: in the stated weight percentages:

Carbon 0.07 Carbon 0.03 0.l 5 s'hcon Silicon 0.10 0.80 Manganese 0. 0 Manganese 0.50 l.0 h Chromium 9.0 l 1.0 Nickel 05 Nickel 0.2 i.0 Molybdenum Molybdenum 1.5 3.0 Vanadium 0.2 0.5 10 Niobium 0.3 0.6 Cobalt Cobalt 3.0 5.0 Copper 2.9 Copper LO Boron 0.012, Boron 0.005 0.020 Nitrogen at least 0.010 but less than (1050 lron and incidental impurities: the balance.

lron and incidental impurities: 5 the balance.

7. An alloy according to claim 1 consisting essentially ofthe 2. An alloy consisting essentially of the following elements followmg elements m the stated we'ght Percentages: in the stated weight percentages:

Carbon 004 ST 0.20 Carbon 0.10 0.20 lvizifig nese 0.75 sliiCOl'l 0.10 0.80 Chromium 10-1 Manganese 0.50 l.0 Nickel 03 Chromium 9.0- l 1.0 Molybdenum 1'5 NlCkei vanadium 022 Molybdenum l.5 3.0 25 Niobium 048 Vanadium 0.20 0.50 Coho" 42 Niobium 0. l0 0.40 Copper 20 Cobalt 2.0 3.5 Boron 0009 oron Nitrogen at least 0010 but less than 0050 Iron and incidental impurities. the balance.

Iron and incidental impurities: the balance.

8. An alloy according to claim 2 consisting essentially of the 3. An alloy according to claim 1 consisting essentially of the following elements in the Stated weight Percentages: following elements in the stated weight percentages:

Carbon C b 0 05 Silicon 0.35 a 0n Manganese Silicon Chromium Manganese Nickel Chro Molybdenum Nlcke] 0.5 0 35 Vanadium Molybdenum 40 Niobium Vanadium 0.22

- Cobalt 3.0 Niobium Co 0 25 4 0 Cobalt 2'0 Boron 0.010 golpp o'olo Nitrogen 0020 O on Nitrogen 0025 Iron and incidental impurities. the balance.

Iron and incidental impurities: the balance. 45

9. An alloy according to claim 2 consisting essentially of the 4. An alloy according to claim 1 consisting essentially of the following elements in the Stated weight percentages.

following elements in the stated weight percentages:

5 Carbon 0.16 Carbon 0- Silicon 0.18 Silicon 0.50 Manganese 0.63 Manganese 0.80 Chromium 9.6 Chromium 9.0 Nickel 2.4 Nickel 0.4 Molybdenum 2.8 Molybdenum 1.5 5 5 Vanadium 0.35 Vanadium 0.20 Niobium 0. l 5 Niobium 0.6 Cobalt 2.9 Cobalt 4.0 Copper 0.40 Copper 1.35 Boron 0.009 9" Nitrogen 0.016 Nitrogen 0.20 Iron and incidental impurities: the balance. Iron and incidental impurities: the balance.

5. An alloy according to claim 1 consisting essentially of the 10. An alloy according to claim 2 consisting essentially of following elements in the stated weight percentages: the following elements in the stated weight percentages:

Carbon 0.06 Carbon 0.1 l Silicon 0.45 Silicon 0.51 Manganese 0.85 Manganese 0.72 Chromium 10.7 Chromium 1 L0 Nickel 0. Nickel 2.3 Molybdenum 1-6 Molybdenum 2.0 Vanadium 0.21 Vanadium 0.31 Niobium 0.46 Niobium 0.1 1 Cobalt 41 Cobalt 2.9 Copper -8 Copper 0.30 Boron 0.010 Boron 0.006 Nitrogen 0.025 5 Nitrogen 0.023

. ron and incidental impurities: the balance. Iron and incidental impurities: the balance.

11. An alloy according to claim 2 consisting essentially of 12. An alloy according to claim 2 consisting essentially of the following elements in the stated weight percentages: the following elements in the stated weight percentages:

Carbon 0. l 6 Carbon 0.18 Silicon 0.49 5 Silicon 0.32 Manganese 0.66 Manganese 0,87 Chromium 10.1 Chromium l0. 1 Nickel 2.3 Nickel 2,4 Molybdenum 3.0 Molybdenum 3,0 Vanadium 0.37 Vanadium 0.38 Niobium 0.20 Niobium 0,23 Cobalt 3.0 10 Cobalt 3.1 Copper 0.25 Copper 0.25 Boron 0.005 B o 0.006 Nitrogen 0.028 Nitrogen 024 Iron and incidental impurities: the balance. iron and incidental impurities: the balance. 

2. An alloy consisting essentially of the following elements in the stated weight percentages: Carbon 0.10 - 0.20 Silicon 0.10 - 0.80 Manganese 0.50 - 1.0 Chromium 9.0 - 11.0 Nickel 1.5 - 3.5 Molybdenum 1.5 - 3.0 Vanadium 0.20 - 0.50 Niobium 0.10 - 0.40 Cobalt 2.0 - 3.5 Copper 0.25 to 2.0 Boron 0.005 - 0.020 Nitrogen at least 0.010 but less than 0.050 Iron and incidental impurities: the balance.
 3. An alloy according to claim 1 consisting essentially of the following elements in the stated weight percentages: Carbon 0.05 Silicon 0.45 Manganese 0.80 Chromium 10.5 Nickel 0.5 Molybdenum 1.5 Vanadium 0.22 Niobium 0.45 Cobalt 4.0 Copper 2.0 Boron 0.010 Nitrogen 0.025 Iron and incidental impurities: the balance.
 4. An alloy according to claim 1 consisting essentially of the fOllowing elements in the stated weight percentages: Carbon 0.07 Silicon 0.50 Manganese 0.80 Chromium 9.0 Nickel 0.4 Molybdenum 1.5 Vanadium 0.20 Niobium 0.60 Cobalt 4.0 Copper 1.35 Boron 0.10 Nitrogen 0.20 Iron and incidental impurities: the balance.
 5. An alloy according to claim 1 consisting essentially of the following elements in the stated weight percentages: Carbon 0.06 Silicon 0.45 Manganese 0.85 Chromium 10.7 Nickel 0.4 Molybdenum 1.6 Vanadium 0.21 Niobium 0.46 Cobalt 4.2 Copper 1.8 Boron 0.010 Nitrogen 0.025 Iron and incidental impurities: the balance.
 6. An alloy according to claim 1 consisting essentially of the following elements in the stated weight percentages: Carbon 0.07 Silicon 0.40 Manganese 0.90 Chromium 10.5 Nickel 0.5 Molybdenum 1.6 Vanadium 0.21 Niobium 0.46 Cobalt 4.2 Copper 2.9 Boron 0.012 Nitrogen 0.012 Iron and incidental impurities: the balance.
 7. An alloy according to claim 1 consisting essentially of the following elements in the stated weight percentages: Carbon 0.04 Silicon 0.20 Manganese 0.75 Chromium 10.1 Nickel 0.3 Molybdenum 1.5 Vanadium 0.22 Niobium 0.48 Cobolt 4.2 Copper 2.0 Boron 0.009 Nitrogen 0.031 Iron and incidental impurities: the balance.
 8. An alloy according to claim 2 consisting essentially of the following elements in the stated weight percentages: Carbon 0.15 Silicon 0.35 Manganese 0.70 Chromium 10.0 Nickel 2.5 Molybdenum 2.5 Vanadium 0.35 Niobium 0.25 Cobalt 3.0 Copper 0.25 Boron 0.010 Nitrogen 0.020 Iron and incidental impurities: the balance.
 9. An alloy according to claim 2 consisting essentially of the following elements in the stated weight percentages: Carbon 0.16 Silicon 0.18 Manganese 0.63 Chromium 9.6 Nickel 2.4 Molybdenum 2.8 Vanadium 0.35 Niobium 0.15 Cobalt 2.9 Copper 0.40 Boron 0.009 Nitrogen 0.016 Iron and incidental impurities: the balance.
 10. An alloy according to claim 2 consisting essentially of the following elements in the stated weight percentages: Carbon 0.11 Silicon 0.51 Manganese 0.72 Chromium 11.0 Nickel 2.3 Molybdenum 2.0 Vanadium 0.31 Niobium 0.11 Cobalt 2.9 Copper 0.30 Boron 0.006 Nitrogen 0.023 Iron and incidental impurities: the balance.
 11. An alloy according to claim 2 consisting essentially of the following elements in the stated weight percentages: Carbon 0.16 Silicon 0.49 Manganese 0.66 Chromium 10.1 Nickel 2.3 Molybdenum 3.0 Vanadium 0.37 Niobium 0.20 Cobalt 3.0 Copper 0.25 Boron 0.005 Nitrogen 0.028 Iron and incidental impurities: the balance.
 12. An alloy according to claim 2 consisting essentially of the following elements in the stated weight percentages: Carbon 0.18 Silicon 0.32 Manganese 0.87 Chromium 10.1 Nickel 2.4 Molybdenum 3.0 Vanadium 0.38 Niobium 0.23 Cobalt 3.1 Copper 0.25 Boron 0.006 Nitrogen 0.024 Iron and incidental impurities: the balance. 